It is previously known in a cellular mobile radio system to reconfigurate a cell by temporarily utilizing an empty traffic channel as a control channel. U.S. Pat No. 5,299,198 and U.S. Pat No. 5,513,183 show a TDMA system in which the number of control channels can be increased by using the traffic channels (see e.g. the Abstract).
WO93/10600 discloses a method of temporarily using a traffic channel as a control channel. The decision for this is made based on comparisons of the traffic density with given threshold values (see the abstract and pages 8, lines 17 to page 9 line 9 and page 15 line 24 to page 17, line 8).
DE 31 30 176 A1 discloses a method in a cellular TDMA-system to convert traffic channels to control channels in dependence on the traffic load. More specific, in dependence on the ratio: number of time slots/number of subscribers in a cell.